Vane impulsion apparatus



5 Sheets-Sheet 1 n.2 Hr! vm mm INVENTOR. MICHAEL J. KRAWACKI BYMW hisATTORNEYS May 10, 1966 Filed May 14, 1962 m om a li @E 3 .gmw N`N\` @NJIMNHMFL [www MQ GMBH .rnv :MMEU NN; L v. llilf N F s a. e #l May 10,1966 M, 1, KRAWACKI 3,250,223

AAAAAAAAAAAAAAAAAAAA Us Filed May 14, 1962 5 Sheets-Sheet z L., me!

INVENTOR L BY f w "mM-J h s ATTORNEYS May 10, 1966 M. J. KRAWACKI VANEIMPULSION APPARATUS 5 Sheets-Sheet :5

Filed May 14 1962 lObb la@ N25 INVENTOR.

MICHAEL J. KRAWACKI KTM,

l( 2 u v GaN-hw@ his A TTU/PNE YS May 10, 1966 M. J. KRAWACKI 3,250,223

VANE IMPULS ION APPARATUS Filed May 14 1962 5 Sheets-Sheet 4 9S FIG 7A96 95 F/G 7B ab his ATTORNEYS May 10, 1966 M. .1. KRAWACKI VANEIMPULSION APPARATUS Filed May 14, 1962 INVENTOR. ICHAEL J. KRAWACKI hisATTORNEYS t 3,250,223 VANE lMPULSION APPARATUS Michael J. Krawacki,Englishtown, NJ., assignor to Trojan Corporation, Plainfield, NJ., acorporation of New .Ierse y Filed May 14, 1962, Ser. No. 194,450

32 Claims. (Cl. 10S- 139) This invention relates generally to vaneimpulsion apparatus and more particularly to improvements in, forexample, the apparatus of such sort which is described in my co-pendingU.S. application Serial No. 853,912 (tiled November- 18, 1959), nowPatent No. 3,033,122, and in British Patent 860,566.

By vane impulsion apparatus is meant apparatus wherein a transfer ofenergy takes place between an expansible or inexpansible uid and one ormore mechanical parts referred to herein as varies Ordinarily, aplurality of vanes are used. The machine which carries those varies iscomprised of rotor and stator units between which there is relativerotational movement, and which are coaxial in the sense that they have acommon axis, and that one unit is surrounded by the other.

The term rotor is used herein in a broad sense to refer to thevane-carrying one of the two mentioned units rather than to indicatethat the unit referred to is rotatable in an absolute sense, e.g., withrespect to the foundation on which the machine is mounted. In otherwords, rotor as used broadly herein is to be taken as pertaining torelative rotation (with the stator) rather than as pertaining toabsoluate rotation. Thus, rotor may be considered as descriptive of thevane-carrying one of the mentioned two units even though thatvane-carrying unit is stationary relative to the foundation for themachine (although rotating relative to the stator), and/ or even thoughsuch vane-carrying unit is disposed outside the stator so as to surroundit.

Returning to a description of the basic character of vane impulsionapparatus, the vanes thereof are carried in a plurality of slot formedin the rotor to be angularly spaced around an annular uid-receivingchannel of which at least part is provided by an annular groove formedin the rotor and surrounding its axis. Each of those slots runstransversely of such channel and opens into such channel on at least oneside thereof, the arrangement of slots and vanes being such that eachvane is transversely movable within its slot between a position at whichthe vane obstructs the channel and a position at which the vane leavesthe channel unobstructed. While one mode of such transverse movement ofthe vanes is axial translatory movement, the terms transverse andtransversely, areused herein in a sense broaded than axial and axiallyfThus, according to the usage herein, the term transversely movable asapplied to the vane is descriptive not only of axial translatory vanemovement, but, in addition, of other types of vane movement as, say,radial translatory, combined radial and axial translatory, angularmovement in a plane transverse to the uid receiving channel, or combined'angular and translatory movement in such plane.

The mentioned fluid-receiving channel has received therein at least onereaction block unit which (in the said relative rotational sense) isfixed as to position in the direction around the rotor axis, and whichis disposed in the channel to obstruct angular flow of fluid therein.Preferably a plurality of reaction block units are used. Inlet andoutlet tluid ports communicate with the channel on angularly oppositesides of the centerline of each block unit. In operation, the rotorrotates relative to the block units. During such rotation, means areemployed to move each Vane within its slot so that, at certain times,the vane is positioned in the channel to obstruct low of duid therein inthe angular direction (i.e., in the direction around the United StatesPatent OF channel), and so that, at other times, the vane is positionedout of the channel to thereby be enabled to pass each reaction blockunit.

When a vane is in huid-obstructing position, the fluid in the channelproduces a diterential in the fluid pressure exerted on the angularlyopposite sides of the vanes. If the relative rotation of the rotor andthe one or more reaction block units is such as to move each vane in thesame direction as the force exerted thereon by the pressuredifferential, the described machine acts as a motor. Conversely, if suchrelative rotation moves each vane in the direction opposite to that ofthe force exerted on the vane by the mentioned pressure differential,the described machine acts as a pump.

Among the objects of my invention are, in connection with vane inpulsionapparatus, to provide alone or in combination any one or more ofthefollowing: ability to vary the volumetric iluid capacity of theapparatus without any accompanying dumping of uid through a routebetween the inlet and outlet ports which bypasses the channel in whichthe fluid does work or has work done thereon,

utilizing iiuid pressure to assist in maintaining the vanes influid-obstructing position, minimizing or compensatingv the net iluidpressure force exerted axially on the rotor, damping of transientvariations in such force, minimizing or compensating for the next fluidpressure force exerted axially and/or radially on parts of the apparatusother than the rotor; improvements in reaction block units and in meansfor maintaining such units in appropriate position, improved sealing-inof the pressurized iluid within an annular channel of the apparatus, andminimization of wear and other undesirable elects due to outwardthrowing of the vanes by centrifugal forces.

The rst named object (variation in the volumetric Huid capacity of theapparatus) is realized according to the invention by providing for theapparatus an abutment means which is axially adjustable relative to therotor, and which cooperates with the groove in the rotor to definetherewith an annular, fluid-receiving channel bounded by arotor-provided side, a rotor-provided bottom, and a side wall furnishedby the abutment means. When the abutment means is axially adjusted inposition relative to the rotor the cross sectional area of the channelis correspondingly varied yto thereby vary the volumetric capacity ofsuch channel.

Preferably but not necessarily, the rotor has formed therein a two-sidedgroove, the abutment means is arcuate in form and tits around at leastpart of the groove bottom, and the said abutment means is axiallydisposed the balancing channel is to offset the axial pressure exertedon the rotor by the working channel iiuid so as thereby -to reduce theimbalance of the axial forces acting on the rotor. In contradistinctionto the balancing channels proposed for prior art devices, the balancingchannel of apparatus according to the invention has means therein toobstruct ow of uid from the one or more inlet ports directly through thebalancing channel to the one or more outlet ports. Thus, such apparatusis adapted to obtain a variation in its volumetric fluid capacitywithout the necessity of resorting to a dumping of some of the fluid,ie., allowing a certain fraction of the stream of uid between the inletand outlet ports to ow therebetween through a balancing channel pathwhich bypasses the 3 working channel, and in which the uid neither doeswork nor has work dorre thereon.

Apparatus embodying the above-described aspects and other aspects of theinvention may take a large variety of forms of which some are indicatedin the aforementioned U.S. patent application and in the aforementionedBritish patent. While certain of the aspects of the present inventionare conned to vane impulsion apparatus of variable volumetric liuidcapacity, others of such aspects are useful both in connection with suchvariable capacity apparatus and in connection with vane impulsionapparatus characterized by a constant volumetric capacity ordisplacement for iluid. Moreover, while the inven- .tion will bedescribed in terms of a vane impulsion pump,

the invention is equally applicable to a vane impulsion motor.

For a better understanding of how the above-mentioned objects and otherobjects of the invention may be realized, reference is made to thefollowing description of exemplary embodiments of the invention, and tothe accompanying drawings wherein:

FIG. 1 is a front elevation in cross section of a variable capacity,vane impulsion pump embodying the present invention, the view beingtaken in cross section in the manner indicated by the arrows 1-1 inFIGURE 2;

FIG. 2 is a View (taken in enoss section transverse to the axis of theFIG. 1 machine 1n the manner indicated by the arrows 2-2 in FIG. 1) cfaportion ofthe FIG. 1

k machine;

FIG. 3 is a view (taken transverse to the axis of the FIG. 1 pump in themanner indicated by the arrow 3-3 in FIG. 1) of another portion of theFIG. 1 machine;

FIG. 4 is a front elevation taken in cross section (as indicated `by thelannows `4-4 in FIG. 9) of the bottom of the 4left hand sleeve in theFIG. 1 pump;

FIG. 5 is anisometric view of one of the reaction block units of theFIG. 1 machine;

FIG. 6 is a developed View of a cross section at the mean diameter ofthe rotor groove and associated parts of the FIG. v1 pump, such viewbeing taken as indicated as FIG. 2 by the arrows 6, 6 of which 6represents the viewing direction and the location of the bottom of theFIG. 6 view, and 6 represents the direction of development of such View;

FIGS. 7A-7E are developed, schematic, cross-sectional views of a portionof the rotor groove (and associated paints) ,of the FIG. 1l machine,such View being maken as indicated in FIG. 2 by the arrows 7, 7' ofwhich 7 represents the viewing direction and the location of the bottomof the FIG. 7 view, and 7 represents the direction of development ofsuch View;

FIG. 7F is a -gnaph tof the net axial force developed at the time ofoperation of the FIG. 1 machine represented by FIGS. 7A-7E;

FIG. 8 is a schematic front view of a modiiication of `one of the sealblocks of the FIG. 1 machine;

FIG. 9 is a view in cross section (taken transverse to the axis of theFIG. l machine in the manner indicated by the a'rnows 9 9 in FIG. 4) vofya fragmentary poirtion of the sleeve of which other details are shownin FIG. 4;

FIGS. 10, 11 and 12 are developed, schematic, fragmentary views (partlyin cross section) of modiiications other than that shown by FIG. 8 ofthe seal blocks of the FIG. 1 machine;

FIG. 13 is a schematic, cross sectional view (taken in a plane normal tothe axis of the FIG. 1 machine) of another modification of such sealblocks;

FIG. 14 is -a developed schematic, yfragmentary view of the exteriorsurface of the tubular liner appearing in FIG. 9 as the uppercross-sectioned member of that lastnamed gure, and

FIGS. 15 and 16 are fragmentary views (partly in cross section `andtaken in a plane through the axis of the FIG. 1 machine) ofmodifications in the seal blocks and right hand vanes of the FIG. 1machine.

'tending axially from end to end of the rotor. Aby FIGS. 2 and 3, thoseslots extend radially into the General structure Referring now to FIGS.1, 2 and 3, the reference v numeral 20 designates a hollow, cylindrical,axially stationary housing which has secured to opposite ends thereof apair of end plates 21, 22. Suitable means (not shown) are provided todrain leakage uid from the entire interior of the housing. Mountedwithin the plates 21 and 22 respectively, are a pair of bearingassemblies 23 and 24 for a rotatable, axially stationary shaft 25passing through central openings in the end plates and surrounded atthose end plates 21, 22 by the stuffing boxes 26, 27 and theiraccompanying glands 2S, 29. The shaft 25 has formed therein a centralfluid bore 30 closed at its left end by plug 32 and connected to theoperating zone of the machine through equiangularly spaced conduits 31(one being shown) extending radially through the shaft.

An axially central portion'of the shaft 25 is formed to provide as anintegral part thereof a rotor 35 of which the general shape is that of acylindrical drum. Formed in the rotor 35 at an axially central positionthereof is an annular groove 40` of rectangular cross section and havingsides 41, 42 and a bottom 43 provided bythe rotor. Also formed in therotor 35 areeight slots'44 (FIG. 2) spaced equiangularly `around therotor and ex- As shown rotor beyond the bottom 43 of the groove 40.

Each of the eight slots 44 contains an axially movable, rectangular vane45 having formed therein a central rectangular notch 46 with sides 47,48 and =a bottom 49. The width of each vane notch between its sides 47,48 is somewhat greater than the width of the rotor groove 40 :betweenthe sides 41, 42 thereof. Moreover, the bottom 49 of each vane notch isradially disposed somewhat inward of the bottom 43 of the rotor groove40. As shown in FIG. 6 by the notch side 48h for the vane 45b, the notchside 48 for each Vane 45 may have a camber.

Disposed in and on diametrically opposite sides of the rotor groove area pair of reaction block units 55a, 55b (FIGS. 2 and 6) whose structurewill be later described in further detail. For the present, it sutiicesto say that each of units 55a, SSb is of arcuate form to rest upon andmake intimate contact with the groove bottom 43 over an angular intervalthereof, Vthat an axial passage 56 for fluid is formed between-the innercurved surface of each unit 55a, SSb and the bottom 49 of each vanenotch when such vane is angularly positioned within the angular intervaloccupied by the unit, and that each of units 55a, 55b extends from sideto side of the rotor grooveA `4t) to obstruct flow of fluid therein inthe angular direction, i.e. in the direction around the rotor axis.

The vanes 45 are moved axially within their slots 44 by a pair ofannular camming faces 59, 60 disposed at opposite ends of each vane tocontact the opposite end faces thereof. Those camming ifaces are the endfaces of a pair of 4annular camming ilanges 61, 62 projecting axiallyoutwards of 4a pair of angularly stationary camming ring assemblies 63,64 to extend into a pair of annular recesses 65, 66 formed in theopposite ends of the rotor 35. The cam faces 59, 60 are shaped toproduce, during rotation of the rotor, an axial shifting of the vane 45in the manner indicated by the dotted line 67 (FIG. 6) whichqualitatively illustrates the locus of the instanaasaaa As so fardescribed, the pump of FIG. l is similar inl structure and advantages tothe apparatus disclosed in the aforementioned U.S. patent applicationand in the aforementioned British patent.

Coming now to a description of some of the dierences between the presentapparatus and the apparatus I have previously disclosed in such US.application and in such British patent, in the now-described apparatusthe camming ring assemblies 63, 64 are positioned at the opposite endsof and threadedly secured to a tubular casing 7l) disposed with asliding fit within the housing 20. While the casing 70 is restrainedfrom angular movement relative to housing 2l) by intermeshing, axiallyrunning splines 71 formed in the interior of the end cap 22 and on theexterior of the casing, the casing 70 is axially adjustable in positionrelative to the housing 20. Such axial adjustment is elected by theturning of a hand wheel 72 on a shaft 73 extending through housing 20 toa pinion gear 74 meshing with a ring gear 75 which surrounds the casing.The interior of the ring gear 75 has helical threading 76 meshing withcorresponding helical threading formed on the exterior of casing 7l).Hence, by the turning of the hand wheel 72 in the appropriate direction,the casing 7G may be axially shifted either leftward or rightward.

The interior surface of housing 2@ and the exterior surface of casing 70are each hollowed out to provide an inlet distribution chamber 79 and auoutlet distribution chamber 80 which are each bounded partly by housing2t? and partly by casing 70, and which each extend annularly around thecasing. Those two chambers are adapted to conduit means (not shown) tobe connected to a huid-providing system so that inlet chamber 79receives fluid from that system and the outlet chamber 80 dischargesfluid thereto. Inasmuch as the FIG. l machine is a pump, the fluidpressures in the inlet and outlet chambers are relatively low andrelatively high, respectively.

A plurality of O rings 81 surround the casing 70 and are axially spacedalong the interface between such casing and the housing in such mannerthat each of chambers 79 and Si) has such a ring disposed to either sidethereof. The O rings 81 act as seals which obstruct axial flow of uidthrough the interface between the casing and the housing. Because ofthis sealing eifect of the rings 81, the casing 70 may be axiallyadjusted in position relative to housing 20 while, meantime, thechambers 79 and 80 are each maintained huid-tight in respect to leakageof uid therefrom through the mentioned interface.

Disposed at an axially central position in its bore, the casinghas aninstanding annular ange 84 encircling the rotor groove. Inlet chamber 79is connected to groove 40 by a pair of oppositely disposed fluid inletports 85a, 85h which each consist of an angularly spaced set of conduits86 passing from the chamber 79 through flange 84 to the groove 4t).Likewise, outlet chamber 8G is connected to the groove 40 by a pair ofoppositely disposed fluid outlet ports 87a, 87h which each consist of anangularly spaced set of conduits 8S passing from the last named chamberthrough the mentioned flange and to groove 40. As shown in FIG. 2, thereaction block unit 55a has an inlet port and an outlet port (ports 85aand 87a) disposed on angularly opposite sides of the centerline thereof,and, similarly, the reaction block unit 55b has inlet and outlet ports85h and S7 disposed on angularly opposite sides of its centerline. Itwill be noted that the inlet and outlet ports alternate around the rotorgroove, the two inlet (low pressure) ports being directly opposite eachother and the two outlets (high pressure) ports also being directlyopposite each other.

The ange 84 is extended inwardly byv a pair of 0ppositely disposed,arcuate seal blocks 90a and 90b of which each is secured to the innercylindrical surface of llange 84 by a pair of pipe plugs 91 (FIG. 6)received in tapered radial holes (not shown) extending through ange S4-and projecting from those holes inwardly of the flange to be threadedlyreceived in the seal block. The two seal blocks together form what isreferred to herein as an abutment means. The arcuate bottom face of eachseal block lits around and is in intimate contact with the bottom 43 ofthe rotor groove 40. In the axial direction, the Width of each sealblock between its axially opposite front and rear faces 92 and 93 isless than the width of the rotor groove 40 between its sides 41 and 42.Accordingly, the seal blocks 90a and 90b divide the rotor groove 40 intoright hand and left hand annu lar huid-receiving channels 9S and 96(FIG. 6) on axially opposite sides of the seal block. For reasons laterapparent, the channel 95 is referred to herein as the working channel,whereas the channel 96 is referred to herein as the balancing channel.

The seal block 90a has formed therein a Huid-conducting passage 97aextending axially along the centerline of that block between its frontface 92a and its rear face 93a. A similar passage 97b is formed in theseal block 90b. Those two passages permit fluid pressure to becommunicated between the portion of working channel 9S into which eachpassage opens and the Portion of the balancing channel 96 into whichsuch passage opens.

Referring to FIGS. 2 and 6, the reaction block units 55a, 55h extendfrom side to side of the groove 40 by passing axially through theopposite gaps by which the oppositely disposed seal blocks 90a, 90b areseparated from each other around the groove. Within the gap occupiedthereby, the unit 55a tits slidably in the axial direction within themargins 10011, 100b which belong to respectively, the seal blocks 90a,90b, and which bound the two angularly opposite sides of such gap. Theunit 556 is similarly fitted slidably in the axial direction within themagins 10151, llb of, respecitvely, seal blocks 90a and 90b and disposedon either side of the gap for unit 5517. Those axial sliding lits of thereaction block units 55a, 55h with the angularly stationary seal blocks90a, 90b serve to maintain the mentioned units angularly stationary inthe direction around the groove despite the fact that such reactionblock units have no connection by a pin or the like to the casing 70. Ithas been found desirable to eliminate such connection in order to avoidthe problem created if such connection were lpresent of a canting ofeach of the units 55a, SSI: around its connection when, duringoperation, the unit is subject to the differential in fluid pressuredeveloped on angularly opposite sides thereof by uid in the vicinitiesof the inlet and outlet ports on opposite sides of the unit. While thereaction block units 55a and 55h are axially tloating relative to thecasing 70 and to the seal blocks attached thereto, such units aremaintained lixed as to axial position relative to the working andbalancing channels 95 and 96 by the sides 41 and 42 of the rotor groove40. Accordingly, the seal blocks 90a, 90b can be adjusted in axialposition Without disturbing the axial positioning of the reaction blockunits. As taught in my aforementioned copending U.S. application SerialNo. 853,912, each of the reaction block units can be anchored to thecasing 70 by a coupling which is comprised of a radial pin and an axialkeyway, the said coupling being one which holds the unit angularlystationary relative to the casing but which permits axial sliding of theunit relative to the casing. A

As will be noted, the forward ends (FIG. 6) 107a, 107 b of,respectively, the block units 55a and 55h obstruct angular ilow of iluidin the Working channel 95, whereas the rear portions of such unitsobstruct angular lHow of fluid in the balancing channel 96. Those rearportions cooperate with the seal blocks 90a, 90b and with the side 41 ofrotor groove 40 to convert angular subdivisions of the balancing channel96 into two chambers 10801, 108b which are disposed behind the rearfaces 93a, 93h of, respectively, the seal blocks 90a, 90b, and whichapproach closely to being fully fluid-tight. Those two chambers Sa, 108breceive uid lfrom the working channel 95 through, respectively, thepassages 97a, 97b in the seal blocks 90a, 90b.

The front face 92a yof seal -block 90a has tabs 105e, 106a (FIG. 6)projecting angularly outwards in opposite directions from the angularlyopposite ends of that front face to overlap in the working channel 95with the angular intervals occupied by the reaction block units 55a,55h. The seal block 90b has -similar tabs 105b, 106k'. Those tabs act asvane-catchers to prevent the vanes 45 from inadvertently being axiallydisplaced by the camming faces 59, 60 (FIG. l) so far towards the frontsof the reaction block units 55a, V55b that the notch sides 48 of thevanes bear against those units. Such inadvertent excess axialdisplacement of the vanes might occur when the mentioned camming facesbecome worn from use, and the vanes consequently t with some playbetween such faces. The reason for avoiding any such undue vanedisplacement and consequent bearing of lthe vanes on the reaction blockunits is that the vanes will tend to become jammed when they so bear.

The arcuate extents occupied by the reaction block units 55a, 55b and bythe seal blocks '90a and 90b are related to certain significant angles(best observed in FIG. 2) which are incorporated in the design of theshown. machine, and Iof which some are as follows: The inter-vane angle(that lbetween the centerline of any two adjacent vanes); the portspread (the angle bisected by the centerline of a reaction block unitand extending from the edge far from that unit of the inlet portadjacent thereto to the edge far from that unit of the outlet portadjacent thereto); the interport angle (that between the edges near t0each other `of the inlet and outlet ports on either side of asealblock). Some other important angles'(best observed in FIG. 6) are: Thedwell interval (that angular interval over which each vane yisstationary or nearly so in its axial position); the camming interval(that angular interval lover which each vane is in axial motion in thecourse in 'its angular movement of passing by a reaction block unit andthen returning to the dwell position for the vane).

Within a port spread, each vane can be considered as subjected at alltimes to equal uid pressures on its angularly opposite sides, whereforethe vane is free to move within its slot. On the other hand, such vanewhen within an interport angle is subjected on its opposite sides to afluid pressure differential which tends to force the vane into frictioncontact with a side of its slot to thereby hinder axial movement of thevane. Because of those considerations, the camming interval (duringwhich the vane is moved) is approximately coextensive with (but may besomewhat greater than) the port spread, and the dwell interval (duringwhich the vane is axially stationary) is approximately coextensive with(but may -be some what less than) the inter-port angle. With suchrelations existing between the port spread, interport angle, camminginterval and dwell interval, evidently the camming intervalsv can beincreased relative to the dwell intervals if, consonantly, the portspreads are increased by decreasing the interport angles until the valueof each of the latter anglesl approaches or (at the limit) reaches aboutthat of the intervane angle. The -intervane angle is about the lowerlimit for the interport angle because, if the interport angle weresubstantially less, then the interport angle would n-ot at all timescontain a Vane, and, accordingly, there would be created an intermittentfluid short circuit between the inlet and outlet ports on either side ofthe interport angle.

As explained in detail in my aforementioned U.S. application andaforementioned British patent, lsubject to the limitation that theinterport angle must not be decreased to the point where there would becreated the mentioned intermittent short circuit, it is preferable thatthe interport angle be made as small as practical in -order to renderthe port spread as large as practical so as thereby to permit amaximizing of the camming interval relative to the dwell interval. Suchmaximizing of the camming interval is advantageous because it lessensthe camimparted accelerating forces on the vanes and the resultant wearproduced by the vanes on the cams, whereby the machine can be operatedat higher rotor velocity to have a higher fluid capacity.

In the presently described machine, the principle of maximizing thecamming intervals is followed in that, as shown in FIGS. 2 and 6, thedwell intervals and interport angles are each only slightly greater thanthe intervane angle, wherefore the cam-ming intervals and port spread ofthe machine are about as large as it is practical to make them in amachine having two reaction block units and eight vanes. Such maximizingof the camming intervals and the port spreads by minimizing of the dwellintervals and interport angles is a feature of such machine whichpermits the arcuate extents of the reaction Iblock units 55a, 5517 to bemaximized relative to the arcuate extents of the seal blocks a, 90b.Thus, in the presently described machine which has two reaction blockunits and two seal blocks, the arcuate extents of the former are almostthree times as great as those of the latter. To so maximize the `arcuateextent of each reaction block unit relative to that of each seal blockis advantageous for reasons later set forth.

Returning now to the elements of the FIG. l machine, a pair of sealsleeves 111, 112 are disposed Within casing 70 on axially opposite sidesof the flanges 84 to each t around rotor 35 with agsmall enoughclearance that only a minimal amount of fluid leakage can take placethrough the interspace between the exterior `of the rotor and theinterior of each sleeve. The right hand sleeve 112 has formed on theinside thereof a plurality of keyways 113 of which each receives as akey the radially outward portion Iof a respective one of the vanes 45carried by the rotor 35 in its slots 44. Hence, the sleeve 112 is keyedby the vanes 45 to the rotor 3S to rotate therewith while, nonetheless,being axially adjustable relative to the rotor. When, during theoperation a vane is positioned so that part thereof is inserted inworking channel and is subjected on its angularly opposite sides toiluid pressure forces of different value, the seating of the outwardportion of the vane in a keyway 113 of sleeve 112 is advantage-ousbecause the inserted part of the vane is thereby supported on threesides (on two sides by slot 44 and on one side by the sleeve keyway)against the ne-t pressure force exerted on that inserted part.

While the sleeve 111 is likewise keyed to rotor 35 to rotate with it butto be axially adjustable relative thereto, in the case of the sleeve 111the keying is accomplished by (FIG. 3) a keying pin 114 received in atapered hole 115 extending radially through sleeve 111, the pin beingdisposed in that hole to have the inner end of the pin project into anaxially running keyway 116 formed in the exterior surface of the rotor35.

The sleeve 111 is axially iitted between the camming o ring assembly 63and the flange 84 (FIG. l) such that annular planar rear and front faces120 and 121 on the sleeve register with respectively matching annularplanar faces 122, 123 on, respectively, the assembly 63 and the side offlange 84 nearest sleeve `111. Similarly, the sleeve 112 tted betweenthe camming ring assembly 64 and the ilange 84 such that annular planarrear and front faces 124 and 12S on the sleeve register withrespectively matching annular planar faces 126 and 127 on, respectively,the assembly 64 and the flange 84.

Each of the sleeves 111 and 112 has formed therein a plurality ofangularly spaced passages 130 (FIG. 3) permitting communication of fluidpressure from the front end of the sleeve to behind the rear facethereof. Those passages form part of separate means which are laterdescribed in detail, and which operatively maintain the front face ofeach sleeve in close up registration with the adjacent matching face onthe side of ilange 84 to provide a iluid seal by the registering faces.As an aid to establising such iluid sealing relation, both the frontface of each sleeve yand the matching face of the iiange'are opticallyor nearly optically tiat surfaces. The seal which is so formed is suchas to preclude all passage of fluid between the registering seal andliange faces except for a minor amount of capillary leakage. Hence, thesleeves 111 and 112 provide radially outward iiuid seals for,respectively, the balancing channel 96 and the working channel 9S.

General operation The operation of the FIG. l machine is describedherein in terms of only the vane 45b thereof. It will be understood,however, that the other vanes of the machine operate in a similarmanner.

The machine is run as a pump by employing an external power source (notshown) to rotate the shaft 25, the rotor 35 and the vanes carried bythat rotor. Assume (FIGS. 2 and 6) that the initial position of vane 45bis its shown position wherein the angular movement of the vane is aboutto bring it into the region underneath the high pressure outlet port87a. As the vane moves into that region, it is subjected to equal (high)values of fluid pressure on the angularly opposite sides thereof. Thus,the vane 45b is free to move in its slot and is, in fact, cammedrightwardly (locus line 67 of FIG. 6) for the purpose of passing thefront end 107a of the reaction block unit 55a. While the vane 4b is sounderneath ports 87a and is so moving rightwardly, the vane does notwork because, in its rotation, it is neither moving with or against anet iiud pressure force exerted thereon in the working channel 95.

The vane 45h continues to be so cammed rightwardly until its angularmotion brings it to the center line of the reaction block unit 55a.There, the axial position of the vane is such that the rotor groove 40and the axial cross section of unit 55a are completely framed within thenotch 46 of the vane (cf. vane 45b as shown in FIG. l). Accordingly, thevane 45h is enabled to pass the reaction block unit.

After so passing the centerline of unit 55a the vane 45h is cammedleftwardly until it returns to its dwell position at that point wherethe vane in its angular movement is a little beyond the end ofprojection 106a on seal block 90a. While the vane is so movingleftwardly, it is mostly under inlet port 85a, and so is in a conditionwhere the vane is subjected to equal (low) fluid pressures on itsangular-ly opposite sides .and is free to move in its slot. While beingcammed leftwardly, the vane does not work because it is angularly movingneither with nor against a net iiuid pressure force exerted thereon inchannel 95.

Soon after the vane has reached the point a little beyond the end ofprojection 106er and has there assumed its dwell position, the vaneangularly moves beyond the port 85a into the interport angle (FIG. 2)between that inlet port 85a and the outlet port 87b. While in thatinterport angle, the notch edge 48b of the vane bears against the frontface 92o of the seal block 90a to cause the part of the vane in workingchannel 95 to act therein as an angularly moving fluid seal. When thevane so seals the working channel, the fluid supplied thereto from inletport 85a is impelled by vane 45h towards the outlet port 87h todischarge into the latter port at a pressure higher than thatcharacterizing the uid at the inlet pormt. Thus, within the mentionedinterport angle, the vane S-b has a pumping action.

The angular movement of the vane in its axial dwell position continuesuntil the vane reaches a point near the end of the projection 10Sa onthe seal block 90a. At this point, the vane has angularly moved 180 fromits assumed initial position and, therefore, has completed one axialcamming cycle consisting of one camming interval followed by a dwellinterval. During the next 180 of rotation, the vane completes a secondsimilar camming cycle. At the end of the second cycle, the vane hasundergone one full revolution. Thereafter, the vane starts a newrevolution in which the vane again experiences two camming cyclessimilar to the ones described. The same is grue for every furtherrevolution undergone by vane 45 During those angular intervals withinthe which the notch side 48h of vane 45h bears against the front face ofone or the other of the seal blocks a, 90b, the shown carnbered shape(FIG. 6) of the notch side 48b aids in maintaining a lubricating wedgeof uid between the vane and the seal block contacted thereby.

The sleeves 111 and 112 rotate with the rotor and with the vanes carriedthereby by virtue of the described coupling in a keyed manner of thesleeves to the rotor. Thus, the front and rear faces on the sleevesundergo rotation relative to the angularly stationary, registeringfaceson the camming ring assemblies 63, 64 and on the flange 84.

In connection with sleeve 112, that sleeve is impelled at lany moment torotate with rotor 35 only by those particular vanes of the rotor whichat that moment are working, i.e. are being subjected to an imbalance inthe uid pressure forces acting angularly thereon. This being so, theremainder of the vanes are free to move Yaxially in the keyways 113 inthe sleeve 112. Thus, the use of the vanes 45 to key the sleeve 112 tothe rotor 35 does not interfere with the axial shifting of the non-Working vanes by the camming faces 59, 60.

So far, the operation of the FG. l machine has been discussed in termsof a working channel having a constant volumetric capacity for fluid.The capacity of that channel may, however, be varied by turning the handwheel 72 (FIG. l) to initiate the previously described chain of eventswhich produces an axial shifting of casing 70 leftward or rightward asdesired. When thecasing is so shifted, it carries with it the cammingring assemblies 63, 64, the sleeves 111, 112, the flange 84, the sealblocks 90a, 90b and the vanes 45 in the rotor, but the rotor 35, itself,its groove 40 and the reaction block units 55a, 55h meanwhile remainaxially stationary. Of course, instead of the casing etc. being axiallymovable and the rotor etc. being stationary, the rotor etc. may beaxially movable and the casing etc, be stationary as taught in LehneU.S.v

Patent 1,042,696. Some incidental effects of the axial shifting of thecasing are to slide both sleeves over the rotor, to produce relativeaxial movement between the seal blocks 90a, 90b and the reaction units55a, 55h and, lastly, to shift the axial position of the seal blocks inrotor groove 40 relative to the sides 41 and 42 thereof.

As the seal blocks yare so shifted leftwardly or rightwardly within thegroove 40, the cross sectional area of the Working channel 95 isdecreased or increased within those angular intervals of the channelwhich are bounded by the seal blocks, and in which the vanes have apumping action. Accordingly, a leftward and a rightward shi-ft of casing70 serve, respectively, to increase and to decrease the effectivevolumetric capacity for uid of the Working channel 95.- Since such ashift of the casing does not affect the position of the vanes relativeto the seal blocks, after any such shift the vanes continue as before tobear against the seal blocks during the dwell intervals for the vanes.Moreover, since a shifting of casing 70 does not 'affect the positionsof the sleeves 111 and 112 relative to the ange S4, after any such shiftthe sleeves continue as before to register in iuid sealing relation withthe ange. While an axial shifting of casing 70 does produce a change inthe mean axial position of the vanes relative to the reaction blockunits, the notches 46 of the vanes are made wide enough to enable thevanes to pass those units for any axial position to which the casing isset. '^Likewise, while the-shift of the casing produces a shift of theinlet and outlet ports relative to working channel 95, those ports socommunicate with that channel that a satisfactory interchange of fluidbetween the channel and the ports continues to take -place for any`axial position to which the casing is adjusted.

As the casing 70 and the seal blocks 90a, 90b are shifted to vary theeffective cross sectional area of working channel 95, a concomitantresult is a variation in the opposite sense of the cross sectional areaof the balancing channel 96. While such vaiiation in channel 96 is notof importance in the FIG. l machine, the presence in the rst instance ofchannel 96 is important. This is so because the axial pressure of theuid in channel 96 opposes the axial pressure of the fluid in channel 95to thereby render the rotor 35 and the casing 70 close to balanced inthe axial direction in respect to the fluid pressure forces thereon.Moreover, such axial balancing of pressure forces is realized withoutany accompanying wasteful diverting of fluid from the working channel 95to the balancing channel 96. How such axial balancing without fluiddumping is obtained is a matter later discussed in detail.

The reaction block unit FIGURE illustrates the details of the reactionblock unit 55a, the structure of unit 55h being similar. As shown, theunit 55a comprises an E-shaped structure of which one element is anarcuate cross arm 135 having a front face 136, a rear face 137 and acircular curvature concentric with the axis of the rotor of the FIG. 1machine. Projecting axially outwards of the front face 136 is a centralarm 140 which furnishes in the unit 55a the part which is the truereaction block, i.e.-the part which acts in working channel 95 toobstruct angular flow of fluid therein.

The center arm 140 is anked on either side by two shorter arms 141 and142 disposed at opposite ends of cross arm 135 and projecting axiallyoutwards of the front face 136 thereof. The axially extending, outerfaces of those two side arms 141 and 142 form the marginal side walls143 and 144 of the unit 55a.

The outer end of the side arm 141 is connected by a web 146 to a portionof center arm 140i back of the front end 107a thereof. The web 146 is ofsmaller radial thickness than the arms 140, 141, is disposed radiallyintermediate the bottom and top faces of those last named arms, and isspaced forwardly of the front face 136 of cross arm 135, whereby web 146has a fluid-conducting space 147 beneath it, another fluid-conductingspace 148 above the web and a third uid-conducting space 149 between theweb and the cross arm 135. A similar web 146' bordered by likeduid-conducting spaces 147', 148', 149 is connected between the side arm142 andthe center arm 140.

To the left (FIG. 5) of the center arm 140, the cross arm 135 isperforated by three fluid passages 150 extending between theduid-conducting space 149 and a pocket 151 formed (FIG. 6) in the rearface 137 of the cross arm 135. A similar set of three uid passages 150'is disposed rightwards of center arm 140 and extends through the crossarm 135 and between the fluid-conducting space 149' and -a second pocket151' formed in such rear face 137.

Considering the unit 55a and its disposition within groove 40 (FIGS. 2and 6), the openings of the outlet and inlet ports 87a and 85a to groove40 are angularly in registration with, respectively, thefluid-conducting spaces 149 and 149 provided by the unit. Thus, the port87a is in fluid communication with groove 4i) by way of spaces 147-149,and, similarly, the port 85a is in uid communication with such groove byway of the spaces l14T-449. Because of the relatively large axialextents of the spaces 148 and 149 taken together and of the spaces 148and 149 taken together, Huid communication is maintained between suchports and the groove for any axial position to which those ports areshifted as a result of axial adjustment in position of the casing 70.

inasmuch as the FIG. 1 machine is a pump, high and low fluid pressuresare manifested in groove 40 underneath, respectively, the outlet port87a and the inlet port 85a. v Both such Huid pressures act axially onthe front expanse of unit a to tend to force it against the side 41 ofgroove 40. The same high and low fluid pressures are, however,transmitted through passages 150, 150 to, respectively, the pockets 151,151 to there exert on the rear expanse of unit 55a a force urging ittowards the side 42 of groove 40. Thus unit 55a is largely balanced withrespect to the axial pressure forces thereon. Because the effective areaover which the same effective pressure acts on the rear and frontexpanses of unit 55a is somewhat less for the rear than for the frontexpanse (due,among other things, to the fact that the combined crosssectional area of pockets 151, 151 (in a plane normal vto the rotoraxis) is less than the cross sectional area of the entire unit), thereisexerted on unitA 55a a moderate net pressure urging the unit towardsgroove side 41. It will be recalled that the unit 55a has no connectionto casing 70 which would constrain that unit from axial movementrelative either to the casing or to the rotor. Hence, such net pressurescauses the unit to bear with moderate firmness against groove side 41irrespective of thermally or wear induced changes in the -dimensions ofthe rotor groove or unit or in the relative axial positions 'of therotor and casing. Such bearing of the unit against that groove side isdesirable since it stabilizes the unit in the angular position assumedthereby around a radially extending axis of turning 155 (FIG. 5) forthat unit, and `since it assures that the rear end of the unit willprovide a good fluid seal between the chambers 108a and 10811 disposedin channel 96 behind, respectively, the seal block a and the seal block90b.

Besides acting on the reaction lblock unit 55a in an axial translatorymanner, the mentioned high and low pressures tend to exert moments onthe unit around axis 155. Considering the effect of the difference inthose two pressures on unit 55a, such pressure differential creates theshown net force P1 (FIG. 5) which acts against the central arm 140, andwhich tends to rotate unit 55a counterclockwise around the axis 155.Simultaneously, however, the same pressure diierential creates the shownnet force P2 which acts between arms 140 and 141 on the face 136 ofcross arm 135 to tend to rotate the unit 55a clockwise around the axis155. Thus unit 55a is designed to produce an approximate equality in thevalues of the opposing moments around axis which the forces P1 and P2set up. Hence, the tendency of unit 55a to cant around axis 155 isminimized.

The stability in positioning of reaction block unit 55a both axially andangularly around axis 155 is further improved by the relatively longarcuate extent ofthe cross arm 135. As was earlier pointed out, sucharcuate extent is almost three times as great as that of each of theseal blocks 90a, 90b.

The fluid in pockets 151, 151' of unit 55a is trapped in those pocketsby the groove side 41 against which the unit is held by the describednet axial pressure acting thereon. A similar fluid trapping takes placein the pockets formed in the rear of unit 55b. The fluid received inchambers 108e, 108b behind, respectively, the seal blocks 90a, 90b istrapped in those chambers by the side walls of the reaction block units(e.g., walls 143 and 144 of unit 55a) which bound the angularly oppositesides of each of those chambers. With both the mentioned pockets and thementioned chambers acting as iluid traps, excepting for a slight amountof leakage, there is no uid flow between the inlet and outlet portsthrough the balancing channel 96. Accordingly, the FIG. 1 machineopcrates without any tluid dumping, i.e.-without any wasteful diversionof duid from the working channel through a by-pass path which includesthe balancing channel, and through which a substantial amount of duidows between the inlet and outlet ports.

Axial balancing by reaction units and seal blocks In the describedmachine, it is preferable to render the rotor balanced in respect toaxial pressure forces thereon for the reason among others of avoidingthe necessity of using thrust bearings to absorb a net axial force onthe rotor. Likewise, it is preferable to have the casing 70 axiallybalanced in order to minimize the etort needed to adjust the axialposition of the casing. The mode of obtaining such axial balancing ofthe rotor and casing will now be discussed.

Within the angular intervals of groove 40 which are occupied by thereaction block units 55a and 551s, the pressurized iluid in the grooveexerts (FIG. 6) a rightwardly directed force on the groove side 42. Thisforce is opposed by a leftwardly directed force exerted on the grooveside 41 by the pockets (c g., 151, 151 of 55a) -formed in the rear facesof the reaction block units. Because the total cross sectional area ofthose pockets in a plane normal to the rotor axis is somewhat less thanthe total cross sectional area of the entire units 55a, 55b (andignoring leakage effects in channel 96), the mentioned leftward force isevidently somewhat less than the rightward one. Such'leftward fluidforce is, however, sup plemented by the described net pressure forceacting on the units 55a, 55b to hold those units against the groove side41 and transmitted `from those units to such groove side. Therefore,over the angular intervals occupied in groove 40 by the reaction blockunits the total leftward torce on groove side 41 is nearly or exactlyequal to the total rightward force exerted on groove side 42, wherefore,the rotor is balanced with respect to the axial pressure forces actingthereon.

Inasmuch as the units 55a, 55h are not secured to casing 70 by anyconnection which would transmit axial force `from the former to thelatter, over those same angular intervals occupied by those units 55a,SSb, the pressurized iluid in groove 40 exerts no axial force on thecasing, and, hence, such casing is likewise balanced over those angularintervals. Because the angular interval occupied by each reaction blockunit is, as stated, almost three times larger than that occupied .byeach seal block, it follows that both the rotor and the casing areaxially balanced over almost three-quarters of the circumference of therotor groove. Therefore, any axial unbalance, of the rotor and casingcan ocur only within the remaining one-quarter (or thereabouts) of thegroove circumference which is taken up by the angular intervals occupiedby the seal blocks.

FIGURE 7A depicts schematically an instant in the operation of the FIG.l machine when the vanes 45f and 45e are at opposite ends of the sealblock 0a. At this instant (represented by point 160 in FIG. 7F), thesame intermediate pressure exists in the interspace 170 ahead (inworking channel 9S) of vane 45e and in the chamber 108e: behind sealblock 90a. Hence, at such instant, the seal block 96a is, for practicalpurposes, axially balanced in respect to the fluid pressure forcesthereon.

In FIG. 7B, the angular movement of rotor 35 has carried vane 45) to alocation where the high pressure uid manifested under outlet port 87b(FIG. 2) and within interspace 169 ahead (in channel 95) of vane 45j hasbeen enabled to ow into chamber 108:1 through the passage 56 (FIG. l)dened between the bottom 49f of the vane notch 461 in vane 451 and thebottom 43 of the rotor groove 49 (cf. vane 5b in FIG. 1). Once in thatchamber 108a, the high pressure fluid is further enabled to flow throughthe passage 97a in seal block 90a to the mentioned interspace 170. Atthis time, the advancement ofthe vane 45f from its FIG. 7A position toits FIG. 7B position decreases the area of the front face 92a (of sealblock 90a) bordering interspace 170 to a size which is somewhat lessthan that of the area of the rear face 93a (of seal block a) which isexposed to the high pressure in chamber 108a. Therefore, at theinstantdepicted by FIG. 7B, there is exerted on seal block 90a aleftwardly-directed, net axial pressure force represented in FIG. 7F bythe point 161.:

Subsequently, the continued advancement of vanes 45]c and 45e causes afurther progressive decrease in the area of front face 92a which isexposed to the high pressure in interspace 170. Meanwhile, the entirearea of rear face 93a is continuously exposed to the high pressure inthe chamber 108:1. Hence, the net leftward axial force on seal block 90abuilds up in amplitude to the peak represented by point 162 in FIG. 7F.

Very shortly after such peak is reached, the machine reaches thecondition depicted in FIG. 7C wherein the vane 45e becomes centered inrelation to the passage 97a through the seal block, the pressure inchamber 108a drops to an intermediate value and the axial unbalance onseal block 90a transiently drops to the zero value represented by point163 in FIG. 7F. When, however, the vane 45e advances only slightlyfarther to its position shown in FIG. 7D, the uncovering by suchvaneadvance ofthe passage 97a permits a iiow of low pressure fluid from theinterspace 171 (behind vane 45e) through passage 97a into chamber 108mAt this instant, the high pressure iluid in interspace is still actingon almost half of the area of the trout face 92a of seal block 90a.Hence, as I represented by point 164 in FIG. 7F, the seal lblock issubjected to a peak value of a net axial force which acts rightwardly.

The continued advance of vane 45e produces aprogressive decrease andincrease in the areas of front face 92a which are exposed to,respectively, the high pressure in interspace 170 and the low pressurein interspace 171. It follows that there is a dropping off from its peakvalue of the net rightward force on seal block 90a. Thus, for example,for the condition represented by FIG. 7E, such force has dropped to thevalue represented in FIG. 7F by the point 165. Such dropping off of thenet rightward axial force continues until vane`45e has reached the sameposition relative to seal block 90a as that shown for vane 45j in FIG.7A. At this instant (represented by point 166 in FIG. 7F), the net axialpressure force on seal block 90a has gone through one complete cycle andis now starting a new cycle identical with the one just described.

From the above, it will be seen that each of seal blocks 90a, 90btransmits to casing 70 an axial force characterized by a sawtoothvariation in amplitude and by alternation in its direction of action.The rotor 35 is subjected to an axial -force similar to that on casing70 excepting that the force on the rotor is out of timephase with theforce on the casing in that the former force acts rightwardly when thelatter force acts leftwardly, and conversely. Because both forces aredeveloped only in the relatively small angular intervals occupied by theseal blocks, and because the alternation in direction of both forcesreduces to zero the average value of each thereof over all but a veryshort time period, neither force is, at worst, particularly troublesome.To the extent they might be found troublesome, the effects of thoseforces can be reduced as desired by increasing the number of vanes perseal block and/ or by increasing the rotor speed.

When the number of vanes per seal block is increased, the inter-vaneangle is decreased to permit a corresponding decrease in the angularinterval which is occupied by each seal block, and of which the lowerlimit of practical size .varies directly with such intervane angle.Evidently, however, the amplitude of the mentioned axial forces variesdirectly with the size of the seal block angular intervals from whichthose forces arise. Hence, an increase in the number of vanes per sealblock and a concomitant decrease in the seal block intervals will serveto decrease the amplitude of the transient axial forces exterted on thecasing and on the rotor.

As a further effect of increasing the number of vanes per seal block,for a given rotor velocity, such an increase produces an increase in therepetition frequency of the sawtooth axial forces. The higher suchfrequency, the lesser the effect of such forces `on the rotor mass andon the casing mass which become progressively less responsive to suchcyclical forces as the repetition frequency thereof increases.Increasing the rotor velocity is, of course, another way by which therepetition frequency of such sawtooth forces may be increased.

Still another Way to minimize the effect of the sawtooth axial force onthe rotor is to damp out the transient variations of such force by meansnow to be described.

Damping mechanism As earlier mentioned, the FIG. 1 machine containsequiangularly spaced conduits 31 which extend through rotor 35 toconnect the interspace between that rotor and sleeve 111 to the centralbore 30 in shaft 25. The bore 30 is in turn connected by way of a radialconduit 180 through shaft 25 to la passage 181 formed at an axiallycentral position in an annular damper disc 182 threadedly mounted on theshaft to rotate therewith. As shown, the passage 181 extends radiallythrough disc 182 to terminate at a clearance 186 between the radiallyVoutward cylindrical surface of disc 182 and a registering cylindricalsurface formed on the inside of end plate 21.

The left and right hand annular sides of damper disc 182 are spacedfrom, respectively, an annular surface formedon the interior of stuliingbox member 26 and an annular surface of a ring member 185 threadedlyreceived 1n end plate 21. Such spacing creates a pair of annular,fluid-receiving, damping chambers disposed on axially opposite sides ofthe disc 182.v To increase the fluid tightness of those chambers, therotating disc 182 has radially inward hub portions projecting axiallyoutwards 1n opposite directions from the center of the disc and havingexterior cylindrical seal surfaces separated only by the smallclearances 187 and 188 from, respectively, an interior cylindrical sealsurface on the stufiing box member 26 and an interior cylindrical sealsurface on the ring member 185.

In operation, fluid from the interspace between rotor 35 and sleeve 111is supplied through conduit 31, bore 30 and conduits 180 and 181 to theclearance space 186, from thence into the damping chambers 183 and 184,and from those chambers through the clearances 187, 18.8 to sump regions(not shown) for the fluid. Because the fluid pressure at the mentionedinterspace is substantially higher than the fluid pressure in such sumpreglons, there occurs from the former to the latter a small but steadyflow of lluid by which the damping chambers 183, 184 are continuouslyreplenished with fluid. If desired, a iiuid collection recess may beformed in one of the reaction block units, and lluid may be conveyedfrom such recess to chambers 183, 184 through conduit means (not shown)passing through elements 70, and 21.

The described mechanism acts as follows to provide damping. When therotor 35 is subjected to a transient axial force urging the damper disc182 leftward, the fluid in damping chamber 183 absorbs that force bybeing discharged from 183 either through the clearance 187 or throughthe clearance 186 to the chamber 184. Conversely, when the rotor issubjected to a transient axial force urging disc 182 rightwardly, `thefluid in chamber 184 absorbs that force by being discharged from thelast named chamber either through clearance 188 or through clearance 186back to chamber 183. Since the chambers 183 and 184 are continuouslybeing replenished with uid, the damper disc 182 and its assoicatedchambers are continuously effective to absorb either rightvwardly FIG. 1machine.

Pressure effects on the vanes Turning back to FIGS. 7A-7E, within theangular intervals occupied by the reaction block units 55a, 55h, thepressure effects onthe vanes are the same as those described in my:aforementioned U.S. application and aforementioned British patent.Thus, when within such an interval, because any such vane, (eg. 45d) hasequal fluid pressure forces acting axially in opposite directions on theopposite sides of its notch, each vane at that time will be 4axiallybalanced in respect to the uid pressure forces thereon. Further, anysuch vane when Within such an interval has equal fluid pressures on theangularly opposite sides thereof, and, hence, the vane is angularlybalanced in respect to huid pressure forces. Still further, any suchvane may be radially balanced with respect to such forces by providingone yor more fluid passages extending in the vane between the radiallyinner and outer margins thereof in the manner described in myaforementioned application and aforementioned British patent.

When the vanes are in the angular intervals occupied by the seal blocks,the pressure effects become more complex. Considering lfor example, thevane 45e as shown in FIGS. 7A-7E, that vane is axially balanced ornearly so when in the position therefor which is shown by FIG. 7A. Aninstant later, however, when vane 45e is in the position shown by FIG.7Bthe vane becomes exposed on its angularly opposite sides to a pressuredifferential caused by a charging of the interspace 170 withhigh-pressure fluid while the fluid in interspace 171 remains at lowpressure.

Such pressure differential forces a small amount of fluid from theinterspace 17 il to the interspace 171 through a leakage path betweenthe notch side 48e of vane 45e and the front -face 92a of seal block 90aagainst which the notch side 48e bears. The fluid in that leakage pathacts on the vane notch side with an effective pressure which is lessthan that in interspace 170 (because, in the leakage path, the pressureis characterized by a dropping gradient from interspace 170 tointerspace 171), but which, nonetheless, exposes the notch side 48e 'toan axial force tending to move vane 45e leftwardly. That force is inpart a function. of the profile of the chamber of notch side 48e. Suchleftward urging of the vane by the intermediate pressure in the leakagepath is, however, more than overcome by the fact that, simultaneously,the rotor slot 44e (which contains vane 45e) becomes charged withhigh-pressure fluid which acts axially on the vane notch side 47e totend to move vane 45e rightwardly. The result is that the vane issubjected to a net axial pressure force which urges the vanerightwardly, and which maintains the notch side 48e of the vane incontact under moderate force with the front liace 92a of the seal block90a.

Thus, as each vane reaches the beginning of one of the angular intervalsin which it works, the vane is automatically positioned by the pressurecondition -to which it is subjected to bear as it should against thefront face of the seal block with which the vane cooperates during theworking interval. Such automatic positioning of the vane by pressure isdesirable since it assures that the Vane will b ear against the sealblock (so as to be properly positioned for working) despite some playbetween the vane and the camming faces 59, (FIG. l) by which the vane ismechanically positioned. If there is any such play, the describedvane-catching projections 106a, 1061? (FIG. 6) on the front faces of theseal block prevent the described net pressure force from displacing avane so far that its vane notch overshoots the axial position of thefront face of asealblock being angularly approached so as, thereby, tocause the vane upon angularly reaching such block to be jammed againstits side.

Turning now to FIGS. 7C and 7D, as the vane 45e moves past the passage97a in seal 'block 90a (FIG. 7D), the rightwardly acting pressure forceon vane notch side 47e drops suiciently in value to be overcome by theleftwardly directed pressure force still being exerted on the vane notchside 48e. Thus, the net axial pressure force one the vane notch sides ofvanes 45e is such as to tend to disengage the notch side 48e of thatvane from the face 92a of the seal block 90a. Even so, the vane stillremains in its proper working position (i.e., with its notch v side 48eagainst seal block face 92a) because of an additional pressure elfectwhich was initially developed when the vane rst started to work (FIG.7B), and which continues until the vane 45e arrives at the locationshown for vane 45)c in FIG. 7A to -thereby reach the end of its workinginterval. Such additional pressure effect is that, as stated, the vane45e when Working is subjected on its angularly opposite sides to apressure differential developed by the high and low pressure tluid in,respectively, the interspaces 170 and 171. Such pressure differentialurges vane 45e against the side of its slot 44e with enough frictionthat the force necessary to move the vane 45e leftwardly against suchfriction is greater than the net pressure force which acts on the notchsides of the vane and which tends to displace it leftwardly.Accordingly, throughout its entire working interval, the vane 45e ismaintained properly positioned by the pressure effects thereon.

As the vanes of the FIG. 1 machine are moved axially during thedescribed camming intervals therefore, the notch sides of each vaneimpel back and forth the huid in the rotor slot within which the vane isseated. If such fluid is inexpansibie and should happen to becometrapped without any outlet between a notched side of the vane and thecenter solid portion of la reaction block uni-t towards which that notchside is moving, then that trapped fluid would block further axialmovement of the vane to produce a locking thereof. Such vane-lockingproblem is avoided in the present machine in the same way as in themachine described in my aforementioned U.S. application and myaforementioned British patent,l

namely, by permitting the uid impelled by the vane notch side to flowfrom one side to the other of the reaction block unit through thepassage 56 (FIG. l) formed between the bottom margin 49 of the vanenotch 46 and the bottom of the reaction block unit.

If the presently described machine should happen to be stopped in theposition shown in FIG. 7C wherein the vane 45e blocks the flow of fluidthrough the passage 97a in seal block 90a, there would occur anundesirable dead center effect. Such effect may be avoided by modifyingthe seal blocks to have the construction illustrated in FIG. 8. A fluidpassage is provided through the seal block of that figure by two holes190s, 191z instead of by the single hole 97a which is shown in FIG. l.The centers of the holes 19012, 191e are spaced apart by the distancebetween thetwo angularly opposite sides of a vane. Hence, there is noangular position of a vane relative to a seal block in which the vanewill block entirely the llow of lluid through the seal block.

Structure and operations of the seal sleeves FIG. 4 is a cross sectionalView taken through a bottom portion of the sleeve 111 as seen in FIG. 1,the cross section plane for FIG. 4 being specifically shown in FIG. 3.The purpose of FIG. 4 is to show in detail the preferred structure forthe seal sleeves. It is to be understood, however, that such sleevesneed not have as cornplex a structure as that shown, but instead, may,for eX- may be simple sleeves which have no fluid passages therein atall.

Corning now to the sleeve structure shown by FIG. 4, the sleeve 111contains at the end thereof 4towards flanges 84 a tubular liner 200 ofdifferent material (as, say, harder material) than the rest of thesleeve. It is such liner which provides for sleeve 111 the annular face121 which (FIG. 1) registers against the matching annular face 123 offlange 84 to form therewith a fluid seal around the outer periphery ofthe balancing channel 96. By providing such face 121 by an element ofhard material, that sleeve face will wear better as it rubs against `thellange face 123 in the course of the rotation of sleeve 111 relative tothe angularly stationary tlange 84.

Although very little fluid passes between the registering faces of thesleeve and of the ilange, the capillary leakage which does occur in theinterface therebetween will act against the area of sleeve face 121 witha pressure which urges the sleeve 111 outwardly so as to tend to open upthe uid seal formed by those faces. Even so, because the pressure in theleakage path through the interface between faces 121, 123 has a droppinggradient in the radially outward direction, the effective value of suchpressure on any angularly positioned part of the area of sleeve face 121is always less than the fluid pressure at the same angular position inbalancing channel 96. Accordingly, the tendency of such leakage pathpressure to force sleeve 111 leftwardly can be more than overcome in amanner as follows.

As stated, the sleeve 111 contains a plurality of axially runningpassages 130 (FIG. 3). As shown by FIG. 4. each such passage isconnected by a slanted conduit 20S to the interface between sleeve face121 and flange face 123 at a zone of such interface which is relativelyclose to the balancing channel 96. At the place where the conduit 205taps into the interface, the pressure of the fluid has a value close tothat of the fluid pressure manifested in channel 96, i.e., is at a valuewhich is still relatively high compared to the effective pressure at thesame angular location by which the luid in the interface acts on thesleeve face 121 to urge the sleeve 111 leftwardly.

Within the sleeve 111, the passage 130 extends rearwardly to anenlargement thereof provided by a deep counter bore 206 of greaterdiameter than such passage, and by, also, an outer shallow counter bore207 of greater diameter than the counter bore 206. Received within theenlargement is a bushing 208 having a stem portion 209 in counter bore206 and a larger diameter head portion in counter bore 207. The bushing208 has formed therein an axially running central passage 210 whichcontinues the passage 130, and which extends from the rear of bushing208 to a pocket 211 formed in the front face of the bushing (i.e.,formed in what is, in effect, the rear face of the sleeve assembly). Asshown, a compression spring 212 is inserted in counter bore 206 behindthe bushing 208 to urge it outwardly so as to maintain its front face120 in contact with the annular face 122 formed on the camming ringassembly 63. As further shown, an O ring 213 is carried by the stemportion of the bushing and is compressed between that stern portion andthe interior of counter bore 206.

The described sleeve balancing structure operates as follows. In theabsence of pressure in balancing channel 96, the resilient force ofspring 212 maintains the face 120 of bushing 208 against the face 122 ofcamming ring assembly 63 and, also, the face 121 of sleeve 111 againstthe face 123 of flange 84, When the channel 96 contains pressurized uid,such fluid under only slightly less pressure than it has in 96 istransmitted through conduit 205, passage and passage 210 (in bushing208) to the pocket 211 formed in the bushing. The fluid which so reachessuch pocket produces on bushing 208 and the counter bore 206 an axialforce which acts with the spring 212 to urge the entire sleeve 111rightwardly.

Thus, there is exerted on the sleeve 111 a total rightward force equalto the sum of the forces developed by the pressurized Huid in all thebushing stem bores plus the sum of the resilient forces developed by allof the springs 212 contained by sleeve 111. While the total of the crosssectional areas (in a plane normal to the rotor axis) of all suchbushing stem bores may be less than the area of the sleeve face 1121which is urged leftwardly by the effective pressure in the interfacebetween that sleeve face 121 and the ilange face 123, because sucheffective pressure is less in value than the average value of the fluidpressures developed in all the bushing stem bores, the total rightwardforce on sleeve 111 from such stem bores may be made equal to or evengreater than the leftward force exerted on the sleeve face 121. Hence,even when the balancing channel contains pressurized fluid, the sleeveface 121 may be urged towards the flange face 123 with about the samevalue of force as that by which the sleeve face was so urged when therewas no pressurized uid in channel 96, so that only the springs 212 insleeve 111 urged the sleeve face towards the flange face. It followsthat, when pressurized fluid is in balancing channel 96, such iluid willnot open up the fluid seal provided by sleeve face 121 and flange face123 but, instead, such fluid may be employed to make that seal eventighter.

As the sleeve rotates, any particular conduit 205 thereof will becarried in alternation through the angular intervals occupied by sealblocks and the angular intervals occupied by reaction block units.`Because there are different fluid pressure values in the reaction unitintervals and in the seal block intervals, the balancing structureassociated with such a particular conduit 205 will experience cyclicaluctuations in the iluid pressure to which the structure is subjected.Such pressure fluctuations for any one such structure do not, however,detract from the described holding by fluid pressure of the sleeve face121 against the face 123 of flange 84. This is so for the reason thatsuch holding effect is produced by the average of the individual holdingactions of all the balancing structures in the sleeve, and consideringsuch average action, there is over any time period and at any instant inthat period, a canceling out with each other of the force variationsarising from the pressure iluctuations manifested in the individualbalancing structures, whereby such force variations are largelyeliminated from the average action.

The pressurized uid in channel 96 acts radially outwards on sleeve 111so that, at high pressure, the end of the sleeve towards ange 84 issubjected to stress which may become unduly high and lead to adeformation of the sleeve in the form of radial expansion of the frontend thereof. Since the liner 200 (FIG. 4) of the sleeve may be of a hardmaterial which is likely to be brittle, it is desirable to relieve suchradial stress by offsetting the outwardly acting force bya force actingradially inwards on the exterior of the liner.

Such inward force is developed by providing in the liner 200 -aplurality of equiangularly spaced holes 230 (FIG. 9) angularly disposedaround the sleeve at positions intervening thosel of the conduits 205.As shown v in FIG. 9, each hole 230 extends from the interior sur :taceof the liner through .the 4liner to a small pocket 231 formed in theliners ex-terior surface. Each such pocket is rendered fluid tight bybeing outwardly bounded by the front end portion of sleeve 111.

As the width of the balancing channel 96 is varied by axially adjustingcasing 70 and the seal blocks 90a, 90b in the manner heretofo-redescribed, a corresponding variation takes place in the inner peripheralarea of liner 200 which is subjected to the high pressure in thatchannel. Such areal variation in turn produces -a correspondingvariation in the t-otal radial force exerted outwardlyon 'the liner. -Inorder to keep the offsetting inward force exerted on the liner (frompockets '231) in step with such variation in the outward force exertedthereon, the holes 2-30 have axial locations which vary from one holet-o the next in the manner shown by FIG. 14.

If channel96 has been adj-usted to be narrow so that Ithe outward forceon liner 200 is correspondingly small, most of the axially distributedholes 230 will open inwardly -on the interface between roto-r 35 andsleeve 1,11 to thereby be cut off from the high pressure fluid inchannel 96. Thus, for a narrow channel'96, high fluid pressure can beconsidered as manifested only in those pookets 231 which are connectedto channel 916 .through the minority of such holes 230 whose inward'openings are not covered by rotor 35. Because those last named pocketsare a minority of all the pockets, the total inward force on -liner 200is small so as lto .be proportioned t-o the small outward force thereon.As, h-owever, the width of channel 96 becomes progressively larger tothereby increase the outward force on the liner, the number of uncoveredholes 230 becomes progressively larger to activate a lgreater number ofpockets 231 to thereby match such increasing outward force on liner 200with a progressively increasing inward force thereon.

FIG. 15 depicts a modiiication of the vane 45 and of the seal blockswhich provides another .way of overcoming the problem of the radiallyoutward force exerted on the sea-l sleeves. In the instance of FIG. 15the force in question is the force exerted on sleeve 112 frompressurized Huid in the working channel 95. As shown by FIG. 15, theseal block 90a is so proportioned in its axial dimension and .is sosecured to the ange 84 that the front face 92a of the seal block istoverhung by a portion of the inner cylindrical surface 240 of theflange. Thus, the outward bound for channel 95 is now provided only in.part by the front end portion of sleeve 112, the remainder of suchoutward bound .being provided by the flange 84. Evidently suchconstruction relieves the radial stress on sleeve 112 in that, of the.tota-l outward force developed by the pressurized uid in channel 95, asubstantial fraction of :that force is received by the flange 84 whichis massive and wel-l adaptedto .absorb the force so exerted thereon.

By increasing the overhang of flange S4 -relative to the face 92a ofseal block 90a so as to increase the outward bounding of channel 95 bythat flan-ge and to corresponding-ly decrease the outward bounding ofsuch channel by theI sleeve |112, the -outward force on that sleeve canbe reduced as desired. For example, as shown in FIG. 16, the flange 84may provide the entire outward bound for the Workin-g channel 95, inwhich case there is no significant outward fluid pressure forceI on thesleeve 112.

In FIGS. 15 and 16, the modiied sleeve 112 is similar to sleeve 111 inthat the sleeve 112 is coupled to rotor 35 by a key and a keyway(neither shown) similar to the -key -114 and keyway 116 described inconnection with sleeve 111 (FIG. 3). A .further similarity is that inthe sleeve 112 of FIGS. 15 and 16 the rotor-carried vanes 45 no longerextend into keyways 113 formed (FIG. 41) on the inside of *sleeve 112.The reason for the omission of such keyways is that, for theconstruct-ion of FIGS. yl5 :and 16, the outer margins of the vanes 45must be radially inward of the inner cylindrical surface 240 of flange84 (and, thus inward of the inside surface. of sleeve 112) in order .forthe vane notch edge 48 of each vane to abut against the front face 92aof seal block 90a during the working interval for the vane.

By not having the radially outer margin of each vane seated in a keywayin sleeve 112, there is lost the previously described feature of athree-sidedsupport for the portion of the vane inserted into workingchannel 95.

'The .absence of such three sided support feature can,

stationary, there can be a closer tit between such rotor and thesurrounding sleeves -to the end of minimizing as a keying means betweensuch sleeve and the rotor.

Further, since the vanes do not project radial-ly outward of therotating assembly, the machine is characterized by the absence of arubbing of the varies on the stator interior or of a shearing by suchvanes of a lubricating film of fluid on the stator interior. Third,inasmuch as the seal sleeves surround the varies, no problem arises fromradially outward throwing of the vanes by centrifugal force. Stillfurther, the described sealing action of the sleeves is an limportantadvantage because, with such sealing action, one doesnt need a close fitbetween the sleeves and casing 70 to provide a sea-l, and, therefore,such lit can be enlarged to reduce ythe viscous drag on the sleeves ofiiuid in .the interspace between the sleeves .and casing 70. All of theadvantages just'enumerated -are realized by the discussed seal sleeveswhen incorporated in a machine of a constant volumetric fluid capacityas well as when incorporated in the presently described type of machine,namely, one havin-g a variable volumetric capacity for fluids. In aconstant displacement machine, the friction between the seal sleeves andthe faces 122, 126 can be eliminated yby using nuts or other adjustablemeans to couple such sleeves to the rotor in a manner whereby thesleeves are out of Contact with faces 122, 126 but can be axiallyadjusted relative to the rotor to control the closeness of tit betweenthe seal sleeves and the ange 84,

It is to be understood that the above detailed description of thepreferred structure for sleeve 111 is also ap- Earlier, a descriptionwas .given of various ways of reducing the etect on the rotor and on thecasing of the sawtooth axial forces generated during angular movement ofthe vanes past the seal blocks 90a and 90b. FIGS. l0, 1l and l2illustrate schematically still other ways by which such effect can bereduced. In these g-ures, the machine under discussion is seen from theside opposite from that from which it is viewed in FIG. 1. lFIGS. -12,the working and balancing channels 95 and 96 are seen as positioned on,respectively, the lcfthand side and the righthand side of the rotorgroove 40.

Referring rst to PEG. l0, in that ligure there is shown as a replacementfor each of the seal blocks 90a, 90b (FIG. l) a modified seal blockconstruction exemplied by a seal block 250 attached by suitable means(not shown) to the inside of ange S4 (FIG. l), the seal block 256 havinga front face 251 and a rear face 252. The face 252 has formed therein arectangular recess or guideway 253 within which is seated an axiallyslidable seal block insert 255. As shown, the rear of insert 255projects axially outward of the seal block face 252 into balancingchannel 96 to bear against the side 41 of rotor groove 46. By so bearingagainst groove side 41, the insert 255 divides the angular intervalbehind block 250 of channel-96 into two fluid-receiving compartments 256and 258 which are each of the same angular width as the insert 255. Athird duid-receiving compartment 257 (of the same angular width as 256and 258) is formed in the guideway 253 forward of the insert 255.

The three compartments 256, 257 and 258 are connected to working channel95 by, respectively, the fluid passages 260, 261 and 262 of which eachextends through seal block 250 along the center line of the compartmentHence, in

associated with that passage. The passage 261 is continued by anotherpassage 263 extending through insert 255 along the center line thereofand between the front of the insert and a pocket 264 formed in the rearface of the insert. The front portion of passage 263 is enlarged by acounter-bore 265 in which is seated one end of a compression spring 266of which the other end bears against the forward closure Wall of theguideway 253.

For a no-pressure condition of rotor groove 40, the resilient force ofspring 265 urges the rear of insert 255 against the groove side 41 toassure that the insert'provide a good duid seal between the compartments256 and 258. After the rotor groove has lbecome lled with pressurizeduid, the pressure thereof in chamber 257 urges the insert 255 towardsgroove side 41 with a force which might be unduly great if not at leastpartly offset. Such offsetting of the last-named force, is, however,provided by the passage 263 and the pocket 264 which serve to oppose theHuid pressure force acting from compartment 257 or insert 255 with afluid pressure force acting from pocket 264 on that insert. In otherWords, the insert 255 is largely axially balanced in respect to theforces thereon in much the same way as axial balancing is (as previouslydescribed) provided for the seal sleeve 111 by the sleeve balancingstructure which was discussed in connection with FIG. 4.

Turning now to the sawtooth axial forces which are generated during theangular movement of, say, vane 45e,V

v divided into three separate sections of which the angular interval ofeach is coextensive with a respective one of c the three compartments256, 257 and 258, and of which each section contains a respective one ofthe fluid passages 260, 261 and 262. As the vane 45e approaches, reachesand passes in succession the passages 260, 261 and 262, the three sealblock sections which respectively contain those three passages each actsin turn as the source of a sawtooth axial force arising from suchsection in the same way as the force shown in FIG. 7F arose (aspreviously described) from the angular movement of vane 45e past theseal block a. Since, however, the three sections of seal block 259 eachoccupy only one third of the whole angular interval occupied by sealblock 90a, and since the amplitude of the sawtooth force varies directlyas the size of the angular interval from which it arises, evidently thethree sawtooth force variations produced by movement of vane 45e pastseal block 250 will each have an amplitude reduced by a factor of aboutthree relative to that or the sawtooth force arising from the seal block90a. Moreover, the repetition frequency of the sawtooth variationsarising from seal block 250 will be greater by a factor of about vthreethan the repetition frequency of the sawtooth variation arising fromseal block 90a. Accordingly, as compared to the seal block 90a, a sealblock ofthe construction shown in FIG. 10 serves to reduce the effectsofthe described sawtooth axial force on the rotor and on the casing bothby decreasing the amplitude of that force and by increasing therepetition frequency thereof.

In Vthe seal block construction shown in FIG. 10, the insert 255 issubjected to a turning moment at that time when the rear end of theinse-rt is acted upon by oppositely directed but unequal forcesgenerated by, re-

spectively, high pressure fluid in compartments 258 and low pressurefluid in compartment 256. Such turning moment on the insert iseliminated by the seal block 270 which is shown in FIG. 11, and which isgenerally similar to the seal block 256 excepting as follows.

In the seal block 270, the angular width of the insert 271 is twice thatof each of the compartments 272, 273 which are sub-divisions of theangular interval behind block 270 of the balancing channel 96, and whichlie to either side of the insert 271. Further, the front face 274 ofseal block 270 contains only two openings 275 Iand 276 for receivingfluid from the working channel 915. As in the case of FIG. l0, one ofthose openings (namely, 276) connects the working channel to afluidreceiving compartment 277 formed in the guideway 27S for insert2711 fonward of the front end of the insert. The other opening (namely,275) is, however, connected by iluid passages 279, 280 and 281 in sealblock 270 to each of the compartments 272 and 273 on either side of theinsert 271. Those last-named passages may be provided in the seal block270 by chasings on the lower or on the upper surface thereof or in someother appropriate manner. Finally (land as a minor consideration), theinsert 2711 is biased rearwardly by two com- .pression springs.

As the vane 45e moves past the opening 275 both of the compartments 272and 273 switch simultaneously from a high pressure to a low pressurecondition, whereiby a change in the uid pressure condition of thosecompartments does not exert any turning moment on the.

insert 27'1. When further movement of the vlane 45e ycarries it pastopening 276, the resulting switch of compartment 278 form a highpressure to a low pressure condition does not generate any turningmoment on the insert. Thus, at no time during the movement of vane 45epast seal block 270 is the insert 27\1 subjected to a turning moment.

Aside from the consideration just mentioned that the insert 271 does notexperience a turning moment, the seal block 270 acts to reduce theamplitude of and to increase the repetition frequency of the discussedsawtooth axial force in much the same manner as does the seal block 250of FIG. 10. In other words, since, as concerns block 270, one sawtoothvlariation of such force arises from the compartments 272 and 273 whichtogether span only one half of the to'tal angular extend of block 270,and since another sawtooth variation of yswch force is next generatedover that remaining half of block 270 which is spanned by thecompartment 277,

*the seal block 270 performs relative to the seal blocks 90a and 90b(FIG. 1) to reduce the amplitude of such sawtooth force by a factor ofabout 2, and to increase the repetition frequency of such force by thesame factor of about 2.

.FIG. 12 illustrates a seal block which extends the principles involvedin the construction of the FIG. lil block so as to eliminate any turningmoment on the seal Iblock insert and so as, at the same time, to reduceby a factor of about three the amplitude of the sawtooth axial force andto increase by a factor of about three the repetition frequency of thatforce. From the descriptions previously lgiven in connection with FIGS.l and 1l, the structure and operation of the FIG. l2 seal block shouldbe self-evident.

FIG. 13 schematically illustrates still another way by lwhich thementioned sawtooth axial forces on the rotor 35 and the casing 70 can bereduced in amplitude and increased in repetition frequency. When, asshown by FIG. 2, the Huid passage 97a and 97b of, respectively, the

Aseal blocks 90a and 90b are on the center lines of those seal blocks,the traversal of vane 45e past block 90a and the traversal of thediametrically opposite vane 45a past the block 90b are actionsgenerating two separate sawtooth axial forces which are in time phasebecause each vane passes at the same moment the uid passage in theassociated seal block. Inasmuch as those two forces are in time phase,the resultant force on the rotor and on the casing is twice theamplitude of the individual sawtooth forces.

When, however, as shown by FIG. 13, the fluid passages 97aand 97b areangularly positioned in the seal blocks 90a and 90b so that thosepassages are, respectively, lagging and leading the center lines 290a,290by of those blocks with reference to the direction of rotation of thevanes 45, then, as the vanes 45e and 45a traverse,

respectively, the blocks 96a and 9ilb,the sawtooth forces generated bysuch traversals will be characterized by a dilierence in time phase. Asa consequence of such difference, the resultant force on the rotor andon the casing will have an amplitude less than twice that of theindividual sawtooth forces, and such resultant force will have as amajor frequency component a repetition frequency which is twice that ofthe individu'al sawtooth forces.

As an alternative to angularly shifting the passages 97a, 97b, away fromthe center lines vof their seal blocks, a difference in the time phaseof the salwtooth forces generated by the traversals of individual vanesover those blocks can be produced by maintaining passages 97a, 97b onthe block center lines, but by using a non-integral num-ber of vanes perseal block. As an example, when the eight vanes 45 (FIG. 2) are replacedby nine equiangularly spaced vanes so that there are fou-r and one halfvanes per seal block, such a difference in time phase will be createdbecause no two vanes will register at the same moment with,respectively, the uid passage 97u and the fluid passage 9717.

Whether the difference in time phase of the sawtooth l'axial forces isproduce-d by using off-center fluid passages or by using a non-integralnumber of vanes per seal block, if only two seal blocks are used, thesawtooth forces fwhich arise therefrom will not be fully time-balancedin ltheir effect on the rotor and on the cas-ing. rIlhis is so because,although such forces are spatially balanced against each other in thatthey act on the' rotor and casing at diametrically opposite zones, thetwo forces do not act on the rotor and easing in the same way at exactlythe same time. A

VWhile the described lack yof a time balance is not usually troublesome,if such a time balance is desired7 it may 'be realized by employing aplurality of pairs of dia-metrically opposite seal blocks individuallyspaced in `an equi-angular manner around the rotor, c g., four sealblocks spaced `at intervals. With such arrangement, when the fluidpassages respective to the blocks in each pair are disposeddiametrically opposite each other, but, lconsidering the seal blocksindividually, such passa-ges vary in their individual angular positionsrelative to the center lines of the associated blocks, then, while thesawtooth forces arising from each seal block pair will be synchronous,4a difference in time phase will exist between the `sawtooth forcesgenerated-by different pairs. of seal blocks. When, instead of movingthe fluid passages away from the center lines of their associatedblocks, the `alternative is adopted of employing a non-integral numberof vanes per seal block (e.g., 10 vanes used with 4 seal 'blocks toyield 21/2 vanes per block), again it will be true that, while thesawtooth forces arising from each pair-of diametrically opposite sealblocks will be forces which are synchronous in time, a difference intime phase will exist between the sets of `sawtooth forces generated bydifferent seal block pairs because of the asynchronous manner in whichthe rotor-carried vanes will register with the iluid passages ofdifferent seal block pairs.

For either of the described ways in which such difference in time phaseis provided by a plurality of pairs -of seal blocks, because of thesynchronism of the forces individual to the two oppositely ydisposedseal blocks in each pair thereof the two forces arising out of each suchpair will act in both a space balanced and a time balanced manner on therotor and on the casing. Accordingly, such rotor land such casing willbe both spaced balanced 'and time balanced in respect to the sawtoothforces generated lby all the pairs of diametrically opposite sealblocks.

The above described embodiments `are being exemplary only, it will lbeunderstood that additions thereto, further modications thereof andomissions therefrom can be made without departing from the spirit of theinvention hereof, land that such invention comprehends embodimentsdiering in form and/ or detail from those specifically disclosed. Forexample, as previously indicated, the invention hereof in many of itsaspects is applicable to a radial machine as well as the axial machinespecifically described. Moreover, each of 4the modications describedherein is usable with any other Aor others of such modifications whichdoes not have a manually exclusive relation with such one modilication.Accordingly, the invention hereof is not to be considered as limitedsave as is consonant with the recitals of the following claims.

I claim:

1. Apparatus comprising, a member which is a rotor in the relativerotational sense, said rotor having formed in it ya two-sided annulargroove, a member associated with said rotor and which is a stator insaid sense, abutment means received in said groove, said `abutment meanstitting around at least part of the bottom of said groove and beingdisposed in said groove to divide it into working and balancing channelson transversely opposite sides of said means, at least one reaction'block fixed. in the direction around said groove relative to saidstator and disposed in said groove to obstruct angular ilow of Huidtherein, inlet and outlet huid ports communicating with said workingchannel on angularly opposite sides of the centerline of said block, aplurality of transversely mo-vable vanes carried by said rotor inangularly spaced slots transverse to and opening into said workingchannel, and means operable by moving each vane in its slot durin-grelative rotation of said rotor and block to permit such vane to passsaid block while at intervening times obstructing angular flow of liuidin said working channel.

2. Apparatus comprising, a member which is a rotor in the relativerotational sense, said rotor having formed in it Va two-sided annulargroove of which the bottom and both sides are provided by said rotor, amember associated with said rotor and which is a stator in said sense,abutment means which is stationary in said sense and which is intransversely spaced relation from both said sides, said abutment meanscooperating with said groove to divide it into transversely opposite,Working and balancing annular fluid-receiving channels each bounded bysaid rotor-provided bottom and by a respective side of said groove andby a respective side wall of said means, and the continuity around saidchannelsof said respec- Itively associated walls being broken by atleast one gap extending transversely from one of said channels to theother between angularly spaced portions of said means, at least onereaction block unit disposed in said gap and having a forwardfluid-obstructing portion in said working channel and a rear portion insaid balancing channel so as to obstruct angular ow of fluid in bothchannels, inlet and outlet huid ports communicating with said workingchannel on angularly opposite sides of the centerline of said block, aplurality of `transversely movable varies carried by said rotor inangularly spaced slots transverse to and opening into said workingchannel, and means operable by moving each vane in its slot duringrelative rotation of said rotor and block to permit such vane to passsaid block While at intervening times obstructing angular llow of liuidin said working channel.

3. Apparatus as in claim 2 in which said unit has a greater transverseextent in said gap than in said Working channel to thereby avoid cantingof said unit around a radial axis in the presence of any looseness of tin said gap of the rear portion of said unit.

4. Apparatus as in claim 2 in which the front expanse in said workingchannel of said unit is subjected on opposite sides of the centerlinethereof Lto a differential in fluid pressure transversely exerted onsaid expanse, and in Awhich said apparatus includes means to apply tothe rear expanse of said unit a transversely directed fluid pressurelikewise characterized by a differential on opposite sides of saidcenterline and opposing the moment exerted on said unit by saidfirst-named pressure difterential.

5. Apparatus as in claim 2 in which said block unit is transverselyfloating in relation to said abutment means, said apparatus furthercomprising means to maintain said unit in transversely lixed positionrelative to said groove.

6. Apparatus as in claim 2 in which the forward end and the rear portionof said block unit are disposed in, respectively, said working channeland balancing channel and occupy relatively narrow and wide vangularintervals in the direction around said groove, and in Which the angularinterval occupied by said rear portion is at least coextensive with theangular interval between the extremities of said inlet and outlet portswhich are farthest removed from the centerline of said unit.

7. Apparatus comprising, a member which is a rotor in the relativerotational sense, said rotor having formed in it a two-sided annulargroove of which the bottom and both sides are provided by said rotor, amember associated with said rotor and which is a stator in said sense,arcuate abutment means which is stationary in said relative rotationalsense and which is transversely adjustable relative to said rotor, saidarcuate means ftting around at least part of said bottom of said groovein transversely spaced relation from both said sides of said groovedivide it into transversely opposite, working and balancing annularfluid-receiving channels each bounded by saidrotor-provided bottom andby a respective side of said groove and by a respective side wall ofsaid means,

` and the continuity around said channels of said respectivelyassociated walls being broken by at least one gap extending transverselythrough said means from one to the other of said channels betweenangularly spaced portions of said means, a reaction block unit disposedin said gap and having a forward duid-obstructing portion in saidworking channel and a rear portion in said balancing channel, said unitbeing in transversely slidable relation with said angularly spacedportions, inlet and outlet fluid ports communicating with said workingchannel on angularly opposite sides of the centerline of said block, aplurality of transversely movable varies carried by said rotor inangularly spaced slots transverse to and opening into said workingchannel, means operable by moving each vane in its slot during relativerotation of said rotor and block to permit such vane to pass said blockwhile a-t intervening times obstructing angular flow of iluidA in saidworking channel, means to adjust the transverse relative positioning ofsaid abutment means and the combination of said rotor and block unit soas to vary the volumetric capacity of said Working channel, and meansadapted during such adjustment to maintain said block unit inytransversely fixed position relative to said groove. v

8. Apparatus comprising, a member which is a rotor in the relativerotational sense, said rotor having formed in it an annular groove ofwhich the 4bottom and at least one side is provided by said rotor, acasing having a radially projecting annular ilange encircling saidgroove, arcuate abutment means extending said llange radially and ttingaround at least part of said groove bottom to define an annularduid-receiving channel bounded 'by said rotor-provided side and bottomand by a side wall of said means, at least one reaction block fixed inthe direction around said groove relative to said means and disposed insaid channel to obstruct angular ow ot iluid therein, inlet and outletlluid ports communicating withV said channel on angularly opposite sidesof the centerline of said block, a plurality of transversely movablevaries carried by said rotor in angularly spaced slots transverse to andopening into said channel, and means operable by moving each vane in itsslot during relative rotation of said rotor and block kto permit suchvane to pass said block while at intervening times obstructing angulartlow of fluid in said channel.

9. Apparatus as in claim S in which said arcuate abutment means is setin under said ange away from said rotor-provided groove side to rendersaid channel outwardly bounded at least in part by said ange.

10. Apparatus comprising, a member which is a rotor in the relativerotational sense, said rotor having formed in it an annular groove ofwhich the bottom and at least one side is provided by said rotor, acasing having a radially projecting annular flange encircling saidgroove, arcuated abutment means extending said flange radially andfitting around at least part of said groove bottom to define an annularfluid-receiving channel bounded by said rotor-provided side and bottomand by a side wall of said means, at least one reaction block fixed inthe direction around said groove relative to said means and disposed insaid channel to obstruct angular liow of tluid therein, inlet and outletfluid ports communicating with said channel on angularly opposite sidesof the centerline of said block, a plurality of transversely movablevanes carried by said rotor in angularly spaced slots transverse to andopening into said channel, means operable by moving each vane in itsslot during relative rotation of said rotor and block to permit suchvane to pass said block while at intervening times obstructing angularflow of fluid in said channel, and a sleeve disposed around said rotorand having an annular front face registering with the side of saidflange to be in fluid sealing relation therewith.

11. Apparatus comprising, a member which is a rotor in the relativerotational sense, said rotor having formed in it an annular groove ofwhich the bottom and at least one side is provided by said rotor, acasing having a radially projecting annular ange encircling said groove,said rotor` and casing being relatively adjustable in the transversedirection, arcuate abutment means extending said flange radially andtting around at least part of said' groove bottom to define an annularfluid-receiving channel bounded by said rotor-provided side and bottomand by a side wall of said means, at least one reaction block fixed inthe direction around said groove relative to said means and disposed insaid channel to obstruct annular flow of fluid therein, inlet and outletfluid ports communicating with said channel on angularly opposite sidesof the centerline of said block, a plurality of transversely movablevanes carried by said rotor in angularly spaced slots transverse to andopening into said channel, means operable by moving each vane in itsslot during relative rotation of said rotor and block to permit suchvane to pass `said block while at intervening times obstructing angularflow of fluid in said channel, a sleeve disposed around said rotor andvanes and having an annular front face registering with the side of saidflange to be in fluid sealing relation therewith, means to adjusttransversely the relative positioning of the combination of said rotorand sleeve and the combination of said casing, flange and abutment meansto thereby vary the volumetric capacity of said channel, and meansadapted during said adjustment to maintain' said annular face of saidsleeve in registering fluid sealing relation with the side of saidflange.

12. A structure adapted for use in vane impulsion apparatus andcomprising, a sleeve having a front annular sealing face an-d a rearface and having formed therein a plurality of huid passages extendingfrom t-he front end of said sleeve to the rear face thereof, saidpassages being enlarged at the rear end of said sleeve, a bushing seatedin slidable relation in each such enlarged portion, and means t-o urgeeach such bushing rearwardly of the enlarged portion in which thelbushing is seated.

13. A structure as -in claim 12 in which the front end of said sleevecontains a tubular liner of harder material than the surround-ing sleeveybody and providing at least a portion of said annular sealing face.

14. A structure as in claim 12 in which said passages communicate withthe interior of said sleeve at the front end thereof.

15. AV structure adapted for use in vane impulsion apparatus andcomprising, a sleeve having a front annular sealing face and a rearface, said sleeve having formed therein a plurality of fluid passageseach extending from the front end of said sleeve to an enlargedcounterbore formed in the rear face of said sleeve to extend axiallyinward thereof, a bushing seated in axially slidable relat-ion in eachcounterbore and having a rearwardly disposed enlarged head in which isformed a rearwardly facing pocket in iiuid communication with the frontof said bushing through a iluid passage formed in said bushing, andmeans to urge t-he head of each Ibushing to project rearwardly of thecounterbore lin which the bushing is seated.

16. A structure adapte-d for use in vane impulsion apparatus andcomprising, a sleeve having a front annular sealing face and a rearface, said sleeve having a plurality of angularly spaced pockets formedin radially spaced relation from a transversely extending surface ofsaid sleeve, and said sleeve providing a plurality of angularly spacedfluid passagesof which each extends radially in said sleeve from saidsurface thereof to one of said pockets.

17. A structure as in claim 16 in which said passages are provided byholes passing through said sleeve and having axially distributedlocations therein.

1S. Apparatus comprising, a member which is a rotor in the relativerotational sense, said rotor having formed in it an annular two-sidedgroove, a member associated with said rotor and which is a stator insaid sense, abutment means disposed in said groove to divide it intoworking and balancing annular channels on transversely opposite sides ofsaid means, at least one reaction block unit fixed in the directionaround said groove relative to said stator disposed in said workingchannel to obstruct angular flow of fluid therein, inlet and outletfluid ports communicating with said work-ing channel o n angularlyopposite sides of the centerline of said 'block unit, a plurality oftransversely movable vanes carried by said rotor in angularly spacedslots transverse to and opening into said working channel, meansoperable 'by moving each vane in its slot during relative rotation ofsaid rotor and block unit to permit such vane to pass said block unitwhile at intervening times obstructing angular flow of fluid in saidworking channel, means providing communication of pressurized fluidbetween said working and bal- 4ancing channels, and means in saidbalancing channel to obstruct the passage therethrough of fluid fromsaid inlet port to said outlet port.

19. Apparatus as in claim 18 in wh-ich said means providingcommunication of pressurized fluid between said working and lbalancingchannels comprises at least one fluid passage extending axially in saidabutment means from said working channel to said balancing channel.

20. Apparatus as in claim -18 in which said means providingcommunication of pressurized fluid vbetween said Working and balancingchannels comprises at least one Ifluid passage extending transversely insaid yblock unit from said working channel to said balancing channel.

21. Apparatus as in claim 18 in which said reaction block unit extendsfrom side to side of said two-sided groove by passing transverselythrough a gap formed in said abutment means, and in which saidobstructing -means in said balancing channel is comprised at least inpart of said block unit.

22. Apparatus as in claim 18 lin which said rotor slots an-d the vanescontained thereby extend transversely on both sides of said groove, eachvane has formed therein a notch within which said block unit `ftswhensuch vane is angularly positioned at the centerline of said block unitand is passing said unit, and each vane obstructs angular flow of fluidin said working channel.

23. Apparatus comprising, a member which is a rotor in the relativerotational sense, said rotor having formed in it and around its axis anannular two-sided groove, a member associated with said rotor and whichis a stator in said sense, abutment means which is stationary in saidrelative rotational sense 'but is axially adjustable relative to saidrotor, said means 'being disposed in said groove axially intermediatethe two sides thereof to divide it into working and balancing annularchannels on axially opposite sides of said means, at least one reactionblock unit iixed in the direction around said axis relative to saidmeans and disposed in said working channel to obstruct angular ilow ofiluid therein, inlet and outlet iluid ports communicating with saidworking channel on angularly opposite sides of the centerline of saidblock unit, a plurality of transversely movable vanes carried by saidrotor in angularly spaced slots transverse to and opening into saidworking channel, means operable by moving each vane in its slot duringrelative rotation of said rotor and block unit to permit such vane topass said `block unit while at intervening times obstructing angular dowof duid in said Working channel, means to adjust the relative axialposition of said rotor and abutment means so as to vary the volumetriccapacity of said working channel, means providing communication ofpressurized lluicl between said working and balancing channels, andmeans in said balancing channel to obstruct the passage therethrough offluid from said inlet port to said outlet port.

24. Apparatus comprising, a rotor having formed in it and around itsaxis an annular two-sided groove, a casing around said rotor on bothsides of said groove and axially adjustable relative to said rotor, saidcasing having an instanding annular ilange encircling said groove,arcuate abutment means extending said tlange inwardly and fitting aroundat least part of the bottom of said groove, said means being disposed insaid groove axially intermediate the two sides thereof to divide it intoworking and balancing annular channels on axially opposite sides of saidmeans, at least one reaction block unit fixed in the direction aroundsaid axis relative to said means and disposed'in said working channel toobstruct angular ow of uid therein, inlet and outlet iuid portscornmunicating with said working channel on angularly opposite sides ofthe centerline of said block unit, a plurality of transversely movablevanes carried by said rotor in angularly spaced slots transverse to andopening into said working channel, means operable by moving each vane inits slot during relative rotation of said rotor and block unit to permitsuch vane to pass said block unit while at intervening times obstructingangular 'tlow of fluid in said working channel, means to axially adjustthe relative positioning of said rotor and of the combination of saidcasing, ilange and abutment means so as to vary the volumetric capacityof said working channel, a pair of sleeves disposed inside said casingon opposite sides of said flange to each surround part of said rotor,said sleeves each having an annular front face registering in -uidsealing relation with thepside near thereto of said flange, meanscoupling each sleeve to said rotor for rotation together whilepermitting relative axial movement between such sleeve and said rotor,means to maintain each sleeve registering in uid sealing relation withsaid flange during said axial adjustment, means providing communicationof pressurized fluid between said working and balancing channels, andmeans in said balancing channel to obstruct the passage therethrough offluid from said inlet port to said outlet port.

25. Apparatus comprising, a member which is a rotor n the relativerotational sense, said rotor having formed in it an annular two-sidedgroove, a casing having an radially projecting annular ange encirclingsaid groove, a plurality of angularly spaced seal blocks extending saidange radially and each llitting around a portion of said groove bottom,said seal blocks being disposed in said groove to divide it into workingand balancing annular channels on transversely opposite sides of saidseal blocks, a corresponding plurality of angularly spaced reactionblock units ot which each extends transversely through a gap between twoadjacent seal blocks and from side to side of said groove to obstructangular ow of iluid in both said'working and balancing channels, inletand outlet fluid ports communicating with said working channel onangularly opposite sides of the centerline of each unit, a`plurality oftransversely movable varies carried by said IBG rotor in angularlyspaced slots transverse to and opening into said Working channel, cammeans operable by mov- -ing each vane in its slot during relativerotation between said rotor and units to permit each such vane-to passeach such unit while at intervening times obstructing angular ow ofiluid in said Working channel, and means to transmit pressurized ltluidbetween said working channel and said balancing channel both in theangular intervals oc-- cupied by said seal blocks and in the angularintervals occupied by said reaction block units.

26. Apparatus as in claim 25 in which the combination of said casings,ilange, seal blocks, vanes and cam means is axially adjustable relativeto said rotor and reaction block units so as to vary the volumetriccapacity of said working channel.

27. Apparatus as in claim 25 .in which there are a fractional number ofvanes per seal block.

28. Apparatus as in claim 2S in which said pressure transmitting meansis comprised for at least one angular interval occupied by a seal 'blockof two iluid passages extending axially in such block and angularlyspaced Iby about the thickness of one of said vanes.

29. Apparatus as in claim 25 in which said pressure transmitting meansis comprised of a plurality of uid -passages of which at least oneaxially extends through each of said seal blocks, and which aredistributed in their angular locations relative to the centerlines ofthe seal blocks through which they extend.

3?. Apparatus comprising, a pair of members which are, respectively, arotor and a stator in a relative rotational sense, said rotor havingformed in it an annular fluid-receiving channel, said stator having anannular radially projecting flange surrounding said channel at least oneangularly stationary reaction block unit disposed insaid channel toobstruct angular ovv of fluid therein, inlet and outlet iluid portscommunicating with said channel on angularly opposite sides of thecenterline of said block unit, a plurality of transversely movable vanescarried by said rotor in angularly spaced slots transverse to andopening into said channel, means operable by moving each vane in itsslot during relative rotation of said rotor and block unit to permitsuch vane to pass said unit while at intervening timesobstructingangular flow of uid in said channel, at least one sleevedisposed around said rotor between said rotor and stator, said sleevehaving an annular front face registering with a side of said flange andhaving a closer fit therewith than the tit Ibetween said sleeve and saidstator.

31. Apparatus comprising, an axially stationary rotor formed to provideat least part of an annular fluid-receiving channel, an axiallyadjustable casing around said rotor, at least one reaction block unittixed in the direction around said axis relative to said casing anddisposed in said channel to obstruct angular ow of fluid therein, aplurality of transversely movable vanes carried by said rotor inangularly spaced slots transverse to and opening into said channel, cammeans operable by moving each vane in its slot during relative rotationof said rotor and block to permit such vane to pass said block while atintervening times obstructing angular flow of fluid in said channel, anaxially stationary housing surrounding said casing and of an interiorshape cooperating with that of the exterior of said casing to form fluidinlet and outlet chambers between said housing and casing, inlet andoutlet fluid ports respectively passing from the consonantly namedchambers through said casing to openings into said channel on oppositesides of the centerline of said -block unit, means to adjust the axialposition of said casing, means axially fixed relative to said casing tobe axially adjusted therewith and to thereby vary the volumetriccapacity of said channel, and seal means disposed between said housingand casing to render said chambers duid-tight while permitting relativeaxial movement between said casing and housing during 'said axialadjustment of said casing.

1. APPARATUS COMPRISING, A MEMBER WHICH IS A ROTOR IN THE RELATIVEROTATIONAL SENSE, SAID ROTOR HAVING FORMED IN IT A TWO-SIDED ANNULARGROOVE, A MEMBER ASSOCIATED WITH SAID ROTOR AND WHICH IS A STATOR INSAID SENSE, ABUTMENT MEANS RECEIVED IN SAID GROOVE, SAID ABUTMENT MEANSFITTING AROUND AT LEAST PART OF THE BOTTOM OF SAID GROOVE AND BEINGDISPOSED IN SAID GROOVE TO DIVIDE IT INTO WORKING AND BALANCING CHANNELSON TRANSVERSELY OPPOSITE SIDES OF SAID MEANS, AT LEAST ONE REACTIONBLOCK FIXED IN THE DIRECTION AROUND SAID GROOVE RELATIVE TO SAID STATORAND DISPOSED IN SAID GROOVE TO OBSTRUCT ANGULAR FLOW OF FLUID THEREIN,INLET AND OUTLET PORTS COMMUNICATING WITH SAID WORKING CHANNEL ONANGULARLY OPPOSITE SIDES OF THE CENTERLINE OF SAID BLOCK, A PLURALITY OFTRANSVERSELY MOVABLE VANES CARRIED BY SAID ROTOR IN ANGULARLY SPACEDSLOTS TRANSVERSE TO AND OPENING INTO SAID WORKING CHANNEL, AND MEANSOPERABLE BY MOVING EACH VANE IN ITS SLOT DURING RELATIVE ROTATION OFSAID ROTOR AND BLOCK TO PERMIT SUCH VANE TO PASS SAID BLOCK WHILE ATINTERVENING TIMES OBSTRUCTING ANGULAR FLOW OF FLUID IN SAID WORKINGCHANNEL.